Process for the production of chondroitin polysulfuric acid esters



Patented Sept. 3Q, 1952 ATE-S PATENT- j Prt'iooEss.-'nort mt 'mcttcmmttctm pn.o 1Tnv; PoLxsULFun1c Aon) .ESTEBS. I It rt" 1yr '.Basel, S, e l nd.Ja S s iiZtoI t se c t h s Nam-m r At l afl aottoter issles tai flo.;249 629 InSwitzerland-October:17," 1950 I 5 Claims. (01. z co zrrs purifying processes havebeen used, mainly dialysis which needs a" great deal of time and puiiflcation by means of barium'salt and-brucine It has how been' fou'nd that chondroitin polyv sulphuricacidesters havingfagood restrictivjacp restrictive action on the coagulation of theblood tion on the coagulation "off-F'the blood "and of some of these" synthetic products gapproaches low toxicity" can be prepared by treating "-ch'onthat of heparin. They are."how'ever, definitely drOitin Sulphuric a'cid iniormamidewith'chloroamor toxic' ::than heparin 'which'fact stro gly smphonic acid-st a o temperature; Itf'is' aidprejudices their use in therapy. vantageous 'to prepare a-mixture1of chlorosul- =:-:Up :to thepresentthese sulphuric acid-"esters "phonic acidand formamide inadvari'ce. 'Onaddhave been produced solely by sulphating the-basic f ing.chondroitin-sulphuric' acid to' such "a rmxture substance with chlorosulphonic acid in pyridine. orsuitable composition a "complete esterjification Other known sulphating methods produce in- 5 occurs in a few hours at room temperature. In active preparations. The sulphation must be this way, a product is obtained which has a sulperformed in such a manner that a high content phur content of over 13% so that no after-sulof sulphur is attained without a substantial phation is necessary. The ratio of chlorosuldiminution in the length of the chain occurring phonic acid to formamide in the mixture used for at the same, time, i. e. a decomposition of the 20 sulphation is of importance with regard to the polysaccharide or polyuronic acid, as it is known that products having a low sulphur content or low molecular weight are only slightly active and temperature of -25 C. then the optimal ratios 3 Slightly influence the wagulation f the have been found to be :100 to 22:100 parts by blood. I I 0 volume. Mixtures of e. g. 14:100 or 252100 parts The sulphation under suitable reaction condiby volume have been found to produce lower tions of different polysaccharides and Polyuronie yields. Because of the solidification of the formacids with chloro lp c in Py p amide or or the formamide/chlorosulphonic acid vides products which have a restrictive action i t t lowest reaction temperature is IItgis known Lthat sterification of. polysacch'aigi'des or .polyuronic. acids withsulphuricacid,

substances can. b" obtainedHwhich hinderithe coagulationl-o e-{bloo'd both in vivo and in vitro and so have properties similar to those ofthe physiological antit-hrombin. heparin. The

substance. If the reaction is performed at a on the co t Such P u s re e. the ited to about 0. The sulphation proceeds more chondroitin polysulphuric acid esters which were first produced in this manner by S. Bergstrom (Hoppe-Seylers, Z. physiol. Chem. 238, 163 (1936)) by'sulphation of chondroitin sulphuric a (c o d it su p c acid about 40. The amountof the chlorosulphonic The process was further elaborated by acid/formamide mixture is so chosen that the re H- Khnig n i- (Helvchim- Acta chondroitin sulphuric acid or polysulphuric acid 3 for the Production of chendroiesters are dissolved therein and the result is a tin polysulphuric acid esters. According to these homogeneous reaction t authors, products are so obtained with a sulphur 40 content which varies between 8.5 and 11.5%. Products which have a lower sulphur content must be after-sulphated in a second process bet t and can be Separated by filtr ti and fore they c b worked D- washed. In this way, a practically complete sep- In pr par n n x iniectable p epar t aration from the other components of the reacweo to this process, Particular care must tion mixture is obtained. Further operations to be taken in Separating the eXeeedingly tOXie remove the adsorptively bound accompanying pyridine which is bound through the chondroitin substances are superfluous as these are quite Pelyslllphuric acid ester partly by alt fo harmless and, in the amounts in which they oction and isalso partly adsorbed as a result of cur, have no effectv on the toxicity of the reaction the colloidal character of the polysulphuric acid r d t ester. Operations which are very laborious and t h b found t t t chondroitin 1. in addition have an adverse influence on the yield phuric acid esters or their sodium salts produced or active substance, therefore, must be performed according t th new process h th some rapidly at temperatures of over 25 but the decomposition of the formamide by the chlorosulbe easily isolated, e. g. byv pouring the reaction mixture into alcohol. The ester then precipito separate this dangerous substance. Many strictive activity on the coagulation of the blood rapidity'of the reaction and the yield of active phonic acid becomes more and more noticeable so that the highest possible reaction temperature is The chondroitin polysulphuric acid ester can as the best preparations produced by sulphation' in pyridine which have been described in the literature. They are, however, considerably less toxic. On intravenous application of the preparations produced according to the present process, the 12L 5!) imouse). is about 1.0 gJkg. whereas that of: the ;preparations .known up to now is 0.25 g./kg. The new process is not only a considerable.

simplification of the previous processes, particu-' larly in the Working up, but alsoimost surprisingly:

provides a different type of product. The products according to the invention are of greatly dissolve well in water with a neutral reaction and are only slightly toxic can be obtained by known methods by reacting with. alkalies.

What I claim is: 1. A method of preparing chondroitin polyv sulphuric ,a cid whichc comprises. reacting chondroitin{sulphuric acid with chlorosulphonic acid in formamide at a temperature between the solidification temperature of the formamidechlorosulphonic acid mixture employed and 40 C.

'2. Aimethod ofpreparing chondroitin polysulphuric acid which comprises reacting chondroitin reduced toxicity while having the same activity I as the previously known products and their toxicological properties as well as their physiological properties regarding the coagulation of the blood sulphuric acid with a mixture of chlorosulphonic acid and formamide containing 100 parts of formamide to 15 to 22 parts of chlorosulphonic acid at a temperature between the solidification temperature of the formamide-chlorosulphonic very closely approach those of the heparin prep arations used in therapy. The following example illustrates the Mar n f parts by volume of chlorosulphonic acid are added to 100 parts by volume of formamidein a flask with astirrer attached under ice cooling."

10 -parts-ofthe sodium salt of chondroitin'sulphuric =acid are added and the temperature is kept at 20-25". C. After 3 hours, the mixture is poureddntojOOparts by volume of methanol and the precipitated chondroitin sulphuric'acid ester is filtered 01f after which it is washed with methv-anol andether. .About 12 parts by volume of ,ester-are obtained with asulphur content of 13 '.I'he;ester is snow-white in-colour. Salts which invenet al.

file of this patent:'

acid mixture employed and-40 C.

3. A method of preparing chondroitin polysulphuricacid which comprises reacting chondroitin sulphuric acid with a' mixture of chlorosulphonic acid and formamide' containing parts of formamide to 15 to 22 partsof chlorosulphonic .acid at a temperature of 10-25 C.

Helv. Chimf Acta, vol, 26,- pages 129651315 (1945). a 

1. A METHOD OF PREPARING CHONDROITIN POLYSULPHURIC ACID WHICH COMPRISES REACTING CHONDROITIN SULPHURIC ACID WITH CHLOROSULPHONIC ACID IN FORMAMIDE AT A TEMPERATURE BETWEEN THE SOLIDIFICTION TEMPERATURE OF THE FORMALDEHYDECHLOROSULPHONIC ACID MIXTURE EMPLOYED AND 40* C. 